60 



SPECIFICITY OF RICKETTSIA PROWAZEKI 



From these lice the following preparations were mader 



Louse No. 



Smears 



W223 



W224 



W225 



Sections 



W217 

 W218 

 W219 



Result of Microscopical 

 Examination 



Rickettsia absent 

 Rickettsia present 



Rickettsia absent 



W 226 Rickettsia absent 



W 227 Rickettsia present 



W 228 Rickettsia present 



Rickettsia absent 

 Rickettsia absent 

 Rickettsia present 



Result of Animal Inoculation 



Guinea-pig 24; Temp. + 

 No control 



Guinea-pig 23; Temp. + 

 Lesions present. Controlled by posi- 

 tive subinoculations 

 Guinea-pig 16; Temp. 

 Proved susceptible to blood from a 

 typhus patient 

 Guinea-pig 10; Temp. 

 Proved susceptible to blood from a 

 typhus patient 

 Guinea-pig 9; Temp. + 

 Proved immune to blood from a 

 typhus patient 

 Guinea-pig 15; Temp. + 

 Lesions present 



Record of Guinea-pig 24, inoculated with the viscera of 

 rickettsia-free louse W 223 



The temperatures of guinea-pig 24 were as follows: 



May 15 102.4 



16 

 17 

 18 

 19 

 20 

 21 

 22 



102.3 

 102.6 

 102.4 

 102.9 

 105.2 

 104.0 

 104.6 



The autopsy showed pneumonia and pseudo-tuberculosis. 



Result: It is very probable that this guinea-pig did receive 

 the virus of typhus and that the course was influenced by the 

 previously existing though latent pseudo-tuberculosis infection. 



Conclusion: Rickettsia-free louse W 223 possibly contained 

 the virus of typhus. An inconclusive experiment. 



